There are certainly good ideas in CL that can help Scheme. Many of the differences are a matter of taste. For those who like small languages, R4RS isn't going away.
But any newcomer will consider the most recent version the default, and assume the others are obsolete. In other languages you seldom ever have a reason to start with an older standard unless you have legacy code to maintain. And that is the reason why they called the whole scam R6RS.
